In a vehicle such as, for example, an automobile, in order to implement an automatic driving control or an automatic light distribution control of a headlamp, it has been proposed to detect other vehicles such as, for example, oncoming vehicles and preceding vehicles existing in the front region of the automobile by providing a camera (imaging device) in the automobile, capturing an image of the front region by the camera, and analyzing the captured image. For example, an adaptive driving beam (ADB) light distribution control has been proposed as a technique for controlling a light distribution of a headlamp of an automobile. The ADB light distribution control is a technique for controlling a part of the light distribution pattern of the high beam light distribution of the headlamp so as not to dazzle other vehicles such as, for example, oncoming vehicles and preceding vehicles detected from the image captured by the camera.
In this technique, in order to implement a highly accurate ADB light distribution control, Japanese Patent Laid-Open Publication No. 2013-147138 proposes a technique in which a camera is disposed in a lamp housing of a headlamp. According to Japanese Patent Laid-Open Publication No. 2013-147138, since the optical axis of the camera comes close to the optical axis of the lamp, the direction of the other vehicle detected from the image captured by the camera, that is, the angle when viewing the other vehicle from the own vehicle coincides or substantially coincides with the angle of the light irradiated from the headlamp. Thus, the ADB light distribution control in the headlamp may be easily and highly accurately performed.
When the camera is disposed in the lamp housing as disclosed in Japanese Patent Laid-Open Publication No. 2013-147138, a part of the light emitted from the lamp unit disposed in the same lamp housing is incident on the lens barrel of the camera directly or after being reflected by the light-transmitting cover, so that white-out due to, for example, halation is likely to occur in the image captured by the camera.